This creature resembles a giant, pale amoeba shot through with stripes of dark gray.

Caught within its protoplasmic form are half-digested creatures of various types and sizes.


XP 1,100 ()

N Large

Initiative –2


AC 12 (natural armor)

hp: 103 (9d10 + 54)

Saving Throws: Con +8

Immunity: Poison damage; paralysis, poison, polymorph, prone, stun, unconsciousness


Speed: 40 ft.

Multiattack: The arcanoplasm slams once and constricts once.

Melee Attack—Slam: +4 to hit (reach 5 ft.; one creature). Hit: 1d6 + 2 bludgeoning damage plus 1d6 acid damage, and the target is grappled.

Melee Attack—Constriction: automatic hit (one creature already grappled by the arcanoplasm at the start of the arcanoplasm’s turn). Hit: 1d6 + 2 bludgeoning damage plus 2d6 acid damage.


Str 15 (+2), Dex 6 (–2), Con 22 (+6),

Int 10 (+0), Wis 14 (+2), Cha 14 (+2)

Languages: Common, draconic (understands but can’t speak)

Skills: Athletics +4, Stealth +0

Senses: Darkvision 60 ft.


Absorb Arcane Energy: Any arcane spell targeted at an arcanoplasm is automatically absorbed into its body. This cures 1 point of damage per 3 points of damage the spell would otherwise deal; nondamaging spells cure 1 point of damage per spell level. Spells that affect an area are not absorbed, but neither do they affect the arcanoplasm. The arcanoplasm can’t absorb magic from spells that it cast itself using arcane spell mimicry, and it can’t absorb divine magic, which affects it normally.

Amorphous: An arcanoplasm can move through gaps as small as 1 square inch without penalty.

Arcanesense: An arcanoplasm can automatically detect the location of any arcane spellcaster within 100 feet. This ability is not blocked by any material.

Arcane Spell Mimicry: As an action, an arcanoplasm can mimic any arcane spell of 4th level or lower cast within 30 feet of it on its next turn. The spell takes effect as if cast by a 7th-level sorcerer (DC 13, attack +6) and requires no components. Because of its innately magical nature, an arcanoplasm adds both its Con and Cha modifiers to concentration checks when it takes damage.



Organization: Solitary

Thought to be the result of a failed magic experiment, wizards and sorcerers alike have tried for years to gather information on this alien creature, but thus far such information has eluded even the most resourceful of researchers.

Arcanoplasms are found in areas where the residual energy of arcane magic lingers. Such areas include abandoned wizard’s towers, keeps, dungeons, and so forth. Here they feed and remain until disturbed. Most encounters with these monsters take place in such locations, as the arcanoplasm rarely travels far from its lair. Because it lairs in and similar places that attract adventurers, it rarely has to wait long between meals.

Arcanoplasms always target arcane spellcasting creatures first. Thanks to its ability to replicate spells cast near it, the arcanoplasm always tries to stay within 30 feet of a hostile arcane caster. Mimicked spells are cast at the foe deemed most threatening.